The detergent formulations for personal hygiene have to be as delicate as possible, since they directly contact the mucous membranes of the genital system, which are very sensitive. Ideally, such formulations should not alter the natural microbial flora also in case of frequent washing, and they should preferably be free of alcohols and strong fragrances, in order to reduce the presence of potentially allergenic substances.
Personal hygiene detergents should not alter the natural acidity of the mucous membranes and must be formulated with ingredients which are not harsh or irritating. In the formulations of personal hygiene detergents available on the market, relatively delicate anionic surfactants are contained, such as sulfosuccinates, acylglutammates, or protein-fatty acid condensates, such as e.g. those derived from the condensation of coconut fatty acids and wheat or oat amino acids. The anionic surfactants are sometimes associated with amphoteric surfactants, such as betaines, or to non-ionic surfactants.
The known formulations sometimes contain long chain alcohols, oils and functional substances, such as plant extracts with a specific action. Among these, chamomile, calendula and lime tree extracts can be mentioned, with a refreshing and soothing activity, as well as thyme extract and Melaleuca alternifolia oil, with an antiseptic activity.
The known formulations for personal hygiene usually have a pH of about 3.5-4.0, corresponding to the vaginal pH.
Despite the measures mentioned above to use surfactants which are as much delicate as possible, to avoid the presence of irritating substances, and to maintain the vaginal pH, the formulations for personal hygiene that are currently commercially available are not completely satisfactory, especially when they are to be used by persons with more or less severe diseases of the external genital mucous membranes, in particular the vulva, for example, lichen and vulvites.
US 2007/269525 A1 discloses O/W gel compositions aimed at providing irritation free formulations, wherein such compositions include 0.05-5% by weight of a polymeric gel former selected from acrylic acid, acrylamide and homopolymers of acrylic acid and acrylamide, 0.1-10% by weight of a wax component, which may be i.a. a C12-18 fatty alcohol or a partial glyceride, and 0.1-30% of an oil component. These compositions may contain “biogenic agents” including i.a. tocopherol and tocopherol acetate in an unspecified amount. The compositions according to US 2007/269525 A1 can be incorporated into body care formulations, the pH of which is not specified.
C. F. Carson et al.: “Melaleuca alternifolia (Tea Tree) Oil: a review of antimicrobial and other medicinal properties” Clinical Microbiology Reviews, vol. 19, no. 1, 1 Jan. 2006, pages 50-62, disclose the disinfectant and antiinflammatory properties of Melaleuca alternifolia oil.